Of various types of networks in which information terminals are connected to one another, wireless communication has advantages over wired communication. Advantages thereof include excellent terminal portability and placement flexibility, and a lightweight body achievable due to elimination of wires. Thus, the wireless communication apparatuses are now used not only for data transmission used with personal computers (Hereinafter referred to as PC), but also for various purposes such as video or audio transmission used with home electrical appliances and online competitive games used with game machines.
An example of the wireless communication, which is commonly used, is a wireless Local Area Network (LAN) system. In general, a topology called an infrastructure mode is used in the wireless LAN system. In the infrastructure mode, a station which is a client machine is connected to an access point which is a host machine. For example, in the case where there are a server PC and a digital TV which are wirelessly connected to an access point and when content stored in the server PC is to be viewed by the digital TV placed in a different room, the server PC once transmits the content data for the digital TV to the access point, and the access point transmits the received data to the digital TV. As described above, in the infrastructure mode, data is transmitted between apparatuses via the access point and thus communication bands cannot be used efficiently, which poses a problem of degradation in communication performance.
To address this problem, there is a technique which performs direct communication between two stations under the same access point so that the communication bands can be used efficiently, thereby allowing an accelerated transmission. FIG. 5 shows a concept of a placement of the access point and stations, and packet transmission. In the direct communication technique disclosed in PTL 1, first, a first station 101 and a second station 102, which are the stations transmit data, exchange a control packet through transmission paths 112 and 113 via an access point 103. When the exchange of the control packet is finished, the first station 101 is capable of directly sending a data packet to the second station 102 through a transmission path 111. This allows the efficient use of communication bands, thereby allowing the accelerated and stabilized communication.